String.prototype.firstUniqueChar = function () {
    let str = this;
    let len = str.length;
    let _char = "";
    let char_Map = {};
    let resultIndex = len;
    for (let i in str) {
        _char = str[i];
        if (char_Map[_char] != undefined) {
            let num = char_Map[_char].Num + 1
            char_Map[_char] = {
                Num: num,
                index: i
            }
        } else {
            char_Map[_char] = {
                Num: 1,
                index: i
            }
        }
    }
    for (let k in str) {
        if (char_Map[str[k]].Num > 1) {
            continue
        } else {
            return { name: str[k], index: k }
        }
    }
}